Reducing speed to 20mph ‘created more deaths than injuries’ but council can’t afford to scrap them

On 22/12/2017 20:40, Ian Jackson wrote:
In message , writes
On Thu, 21 Dec 2017 19:42:28 +0000
Ian Jackson wrote:
In message , Nightjar
writes
On 21-Dec-17 11:09 AM, wrote:
...
I doubt anyone expects cars to stick to 20 anyway. I imagine the
thinking
behind it is that at 30 cars do anything up to 40 so put 20 signs
up and
they'll do 25-30 which is acceptable.

The aim really is to reduce speeds to 20mph, or not much above it. This
is based upon the 1979 findings that pedestrians struck by a car doing
30mph have a 20% risk of dying, as compared to 2.5% at 20mph. More
recently, this has been revised down to 8% and 1.5%, which may be due
to improvements in vehicle design since the first report. However, it
is the most ignored limit of all, with 84% of cars exceeding 20mph, as
compared to 46% exceeding 70mph on motorways.

One problem is that if there is an accident because of 'speeding', there
is often an immediate call to lower the speed limit - with little
reference to how fast the offending vehicle was actually going. I recall
near here there was fatal accident on a 50mph limit main road. Some
people wanted a 40 limit - despite the vehicle's estimated speed being
at least 80mph. The obvious answer might be simply be to enforce the
existing limits.

Unfortunately a lot of councils do that with speed humps which limit your
speed to far lower than the posted limit (which is probably
deliberate) unless
you want to pay for expensive suspension repairs. If you even did 20 over
some speedhumps you'd **** one or more struts, never mind 30. I find I
have
to crawl over some at not much more than 10 or my car risks bumping
its stops.

In my local town, there are 13 speed bumps in a 30 limit, all in a
distance of about 600 yards. They are the individual, rectangular type,
in pairs - one on each half of the road.

Motor bikes can pass between the bumps, or on either side. Chelsea
Tractors (which comprise at least half the vehicles in this affluent
part of the world) can usually completely straddle one the bumps. It's
really only those with 'ordinary' cars with a 'normal' wheel width that
really suffer. You have the choice of having either the left side or the
right side of the car experiencing the full lift of centre of the a
bump, or partially straddling it -Â* with both sides of the car getting
only a partial lift as the wheels pass simultaneously over both of the
sloping shoulders.

Despite it being a 30 limit, I wouldn't dream of passing over any of the
13 bumps at more than about 20mph. As I resist the temptation to
accelerate between the bumps, I end up travelling the whole 600 yards at
20. [I don't mind this at all - and would indeed be happy to do the same
if there was a bump-less 20 limit.] However, I then often end up with a
procession of vehicles following me at 20mph. There are occasions when
one vehicle will suddenly break rank, and tear off furiously to the
front of the procession at a hell of a lot more than the 30 limit. As
the road with the bumps ends at a 'Give Way' sign at a T-junction with
another road, I usually reach the end immediately behind the vehicle
that couldn't wait behind me, waiting at the Give Way sign.

The whole thing is crazy.



If you take the humps at the sharpest angle you can, then one wheel at a
time goes up and the overall shock is massively reduced.